Method of and apparatus for heating hydrocarbon oils and components thereof



A. E. NASH ET AL Oct. 11, 1938.

METHOD OF AND APPARATUS FOR HEATING HYDROCARBON OILS AND COMPONENTSTHEREOF Filed May 16, 1934 3 Sheets-Sheet 1 1 um 2w R aw Mm Rb smu E MNQ6 638% WEED-N GERWQQQQLQ IN ENT R3 ZZM'ATTORNEY.

Oct. 11, 1938. A. E. NASH ET AL METHOD OF AND APPARATUS FORHEATINGHYDROCARBON OILS AND COMPONENTS THEREOF Filed. May 16, 1934 3Sheets-Sheet 2 INVENTORS l M w ATTORNEY.

- i i n n n N N i n i A. E. NASH ET'AL 2,132,964

3 Sheets-Sheet 3' 5335 Man Oct. 11, 1938.

METHOD OF AND APPARATUS FOR HEATING HYDROCARBON OILS AND COMPONENTSTHEREOF Filed May 16, 1934 1\ =1 .I' y) kuobw do v INVENTORS M 1 63MWMATTORNEY. I

kwk s A V baw W WSRQQQQM Patented Oct. 11, 1938 V UNITED STATES METHODOF AND APPARATUS FOR HEATING HYDROCARBON OIL THEREOF Arthur E. Nash,Mount Airy,

Jenkintown, Pa., assignors Franklin E. Shelly,

S AND COIVIPONENTS Philadelphia, and

to Alcorn Combustion Company, Philadelphia,

Pa., a corporation of Delaware Application May 16, 1934, Serial No.725,940

8 Claims.

Our invention relates to methods of and apparatus for heating fluids,and especially oils;

and more particularly for heating petroleum or which the petroleum and/or components are separable into oils, generally in vapor or vaporousand liquid phases, comprising components of boiling ranges less than theboiling range of the charging stock, and the oils so separated from eachother .are then individually heated under conditions differing in one ormore of the conditions of temperature, pressure, rates of heating and/orperiods of time, to crack them or effect their conversion into lowerboiling hydrocarbons to better advantage or with better results than ifthe hydrocarbon oils or charging stock were as a whole subjected tothesame conditions; and more particularly in accordance with our inventionone of the aforesaid separated components may be further separated intofurther components which are then individually heated, generally underdifferent conditions.

Further in accordance with our invention, the components which have beenseparated and individually heated under different conditions maythereafter be separately further treated or, and generally, they may berecombined and together passed through the system for one or morefurther steps of treatment.

7 Further in accordance with our invention, the separated components areindividually heated in different zones of a furnace or heating system,generally by radiation and/or radiation and convection, and the heatingpreliminary to the separation of the oil into its aforesaid componentsis effected, generally, largely by convection, by a combination of gasstreams from the several zones of the furnace or heating system.

More specifically in accordance with our invention, the several stepscomprised therein, that is, the preliminary heating, the separation intofractions or components, and the individual heating of the components,are all accomplished under pressure'to which the oil or petroleum israised either before or after the first heating step. By thisarrangement only a single hot oil pump is required for handling bothcomponents or fractions of the heated oil, the pressure developed bythis single pump being suificient to force the oil through the completeconversion or treating system, and particularly to maintain when desiredon the several components pressure or pressures, generallysuperatmospheric, suitable to the temperatures to which the componentsare raised while individually or separately heated.

For a better understanding of our invention, together with other andfurther features thereof, reference is had to the following descriptiontaken in connection with the accompanying drawings, and its scope willbe pointed out in the appended claims.

In the drawings, Fig. 1 is a diagrammatic representation of a system forconverting or treating hydrocarbon oils, including our improved heatingsystem, and showing in cross-section a furnace particularly suitable forheating hydrocarbon oils in accordance with our invention.

Figs. 2 and 2a are longitudinal and cross-sectional views, respectively,of a separating apparatus suitable for use in connection with ourimproved system, while Fig. 3 shows a modified form of our inventionemploying two separators and applied to a modified cracking orconversion process.

Referring now more particularly to Fig. 1 of the drawings, there isshown a complete oil conversion system embodying our invention, the flowof oil through the system being as indicated by the arrows. Fresh oilstock is supplied to an inlet l and passes therefrom through suitablestorage tanks or receivers II from which it is drawn by a pressurebooster pump I2 and passed through a heat exchanger, indicatedschematically at I3, to be referred to hereinafter. The oil, afterpreliminary heating in the exchanger !3, is drawn by the hot oil pump I4and forced under pressure to the main heating apparatus or furnace ofthe system. This heating furnace may be of any of the several well-knowntypes, although we have illustrated a furnace particularly suitable foruse in our invention and comprising side-wall and roof structures l5 ofsuitable refractory material. Associated with the outer side walls l5are a pair of independently adjustable or controllable burners. l6 andI1 and cooperating auxiliary combustion chambers l8 and I9,respectively, having walls and/or top plates of highly refractorymaterial, such as silicon carbide. It will be understood that anydesired type of fuel, such as oil, gas, or pulverized solid fuel may besupplied to the burners I6 and II. The housing structure of the furnacecomprising the walls and roof structure l5 defines a plurality ofcompartments, fire chambers, or zones A and B separated by uprightbarriers or bafiles 20 also of refractory material. The baffles 23 maydefine, also, a third heating compartment or zone C. The currents of hotcombustion gases from the chambers I8 and I9, passing outwardly andupwardly through the zones A and B, combine and pass downwardly throughthe zone C.

In the zone C is disposed a heat-absorption structure, such as a bank ofoil-conducting tubes 2I, connected, as illustrated, to the hot oil pumpI l. The tubes 2| are washed or swept by the currents of hot combustiongases and are adapted to be heated preponderantly by convection,although, in some instances, a certain amount of radiant heating may beeffected, particularly in the upper portion of the zone C, by virtue ofthe baffles 23 reaching radiant temperatures.

After a mechanical preliminary heating in the bank of tubes 2 I, the oilis conducted to a separating apparatus S which may be of any severalwell-known types, although I have shown in Figs. 2 and 2:1, by way ofexample only, one structure suitable for this purpose. As shown indetail in these figures, the separator comprises a substantiallycylindrical casing 22 with a top plate 23. The lower portion of thehousing 22 converges into a conical chamber 22a connecting with, aliquid outlet 24. Depending from the top plate 23 are aseries of baiileplates 25 arranged in staggered relation, as shown clearly in Fig. 2a,providing a tortuous path for the combined vapors and liquids from thebank of tubes 2| in passing from the inlet 23, through the separator Sand to the vapor outlet 21 and liquid outlet 24.

The vapor outlet 21 is connected to a bank of roof tubes 28, a bank ofwall tubes 29, and a bank of floor tubes 30, all disposed in the zone Aof the heating furnace. The liquid outlet 24 is connected to similarlyarranged banks or groups of tubes 3 I, 32 and 33. As stated above, thebank of tubes 2| is disposed in the path of the combined currents ofgases from the combustion chambers I8 and I9, to be heatedpreponderantly or substantially solely by convection. On the other hand,the banks of tubes 28, 29, 3| and 32 disposed adjacent the roof and sidewalls of the furnace chambers may be partially wholly outside of thepaths of the currents of gases through the furnace, and may receive heatpreponderantly or substantially solely by radiation, although, in cer=tain instances, it may be desirable to so relate these banks of tubes tothe currents of gases that they receive also a component of heat byconvection from the gas streams. The banks of floor tubes and 33 areheated preponderantly or substantially solely by radiation from thecurrents of gases, which pass inwardly and upwardly from the combustionchambers I8 and I9 sweeping or washing the banks of tubes 39 and 33 toan inconsiderable extent.

Ordinarily, it is desirable to conduct the second stage of heating ofthe liquid component of the oil at a reduced pressure and, for thispurpose, a pressure-reducing valve 34 is interposed in the connection tothe liquid outlet 24. The vapor and liquid components orfractions, afterpassing through the second stage of heat-absorption structures justdescribed, are recombined into a common outlet. In order approximatelyto equalize their pressures before recombining, a

pressure-reducing valve 35 is connected in the outlet from the bank oftubes 30. In addition, it may be desirable to include apressure-reducing valve 36 in the common outlet of the banks of tubes 39and 33 before passing the combined vapors and fiuid through theremaining stages of the cracking or refining system.

The combined vapors and fluid thus subjected to preliminary heating maybe further cracked, refined or converted in accordance with any desiredmethod or system. By way of example only, we have shown one such systemin which the common outlet for the combined vapors and fluid isconnected to the inlet 38 of an evaporating tower 39 to which isconnected also a conduit 3'! leading to a supply of cooling oil. Thetower is provided with a live steam inlet 4!! connected to a spray 4|disposed in the bottom thereof. In addition, an inlet 42 for reflux oilis provided in the top of the tower 39 and connected to a spray 43. Anoutlet 44 effective to draw ofi the unconvertible or tarry residues,this outlet being connected to a coil 45 of the heat exchanger I3.

The outlet 46 of the evaporator 39, through which passes the combinedvapors and liquids, is connected through a conduit 41 to the inlet 48 ofa fractionating column 49. The column 49 has a reflux oil inlet 50connected to a spray 5| situated in the top of the column. The loweroutlet of the column 49, for the unconverted or uncracked liquid orliquid components of the oil, is connected to a cooling coil orcondenser 52, the outlet of which is connected to the oil stock inletIII. The cooling coil 52 is connected also through a reflux pump 53 tothe reflux inlet 42 of the pre= ceding evaporating tower.

The outlet 54 of the column 49, for the converted or cracked vapors, isconnected to a condenser 55 which, in turn. is connected to the inlet 56of a distillate receiver 51, in which the several components areseparated by gravity or otherwise. The receiver 5-! has an outlet 58 forgas, which may be used for illumination, industrial or demestic heating,or the like, an outlet 59 for gasoline, and an outlet 60 in the bottomthereof for drawing off the water condensed from the processing steam. Aportion of the gasoline thus produced may be drawn through the conduitii! by a reflux pump 62 connected to the reflux inlet 50 of thepreceding fractionating column 49.

The operation of the above-described apparatus for conducting thepreliminary heating of the oil will be well-understood from theforegoing description. In brief, the fresh oil stock, together with anyunconverted oil from the fractionating column 52, is passed through theheat exchanger or economizer I3 by the booster pump I2, the exchanger I3being effective only to conserve heat remaining in the tarry residuesflowing from the evaporating tower 39. This preheated oil is then drawnby the hot oil pump I4 and forced through the bank of tubes 2| locatedin the zone C of the furnace chamber. The oil is heated moderately inthis bank of tubes and reaches a'temperature, for example, of 600 or 800F. During this preliminary heating, certain of the lighter fractions orcomponents of the oil are vaporized.

The combined vapors and liquid flow from the bank of tubes 2| to theinlet 26 of the separator S, the mixture impinging upon the staggeredbaffles 25, which aid in separating the liquid from the vapors, theliquid draining down the baflies 25, as indicated by the arrows in Fig.2, and the vapors passing threugh the tortuous path between the bafliesand to the outlet 21. As shown, the separator S forms a neutraltemperature and reaction zonesinceheat is neither added to norsubtracted from the stock which at this time is not subjected to furthertreatment. As already indicated, the sole function of the separator S isto separate mechanically the stock into its liquid and vaporouscomponents. From the outlet 21 the vapors are passed through the banksof tubes 28, 29 and 30 where they are raised to their final crackingtemperature which, by way of example only, may be in the neighborhood of1000 F. The liquid component passes through the outlet 24 of theseparator S, the pressure-reducing Valve 34, and through the banks oftubes 3|, 32 and 33 in which it is heated to its final cracking orconverting temperature, which, by way of example only, may be in theneighborhood of 900 F.

By this means, the original oil stock is converted into two components,each of which is more homogeneous than the entire stock, and each ofwhich may be cracked or refined at a temperature better suited to itsparticular physi cal and thermal characteristics. Thus, a maximumcracking or converting takes place without over-cracking or coking ofthe heavier compo nents, which might take place if they were subjectedto the higher temperatures to which the lighter components are heated,or without the under-cracking or incomplete conversion of the lightercomponents, which would result from treating the whole stock at thelower temperature of the liquid component.

It will be understood that the particular connections and arrangementsof. the several banks or groups of oil-conducting tubes in the zones ofthe furnace chamber are purely illustrative, and that any otherarrangements or combinations of banks of tubes may be utilized for theseveral heating stages; that is, the initial heating of the whole oilstock and the final heating of the two components. It will beunderstood, also, that .the disposition of the several banks of tubeswithin the furnace may be such as to transfer heat thereto in theseveral zones by radiation, convection, or combined radiation andconvection, in accordance with the requirements of the particularfurnace and the particular oil stock which is being treated. Further,the several stages of heating may be effected by any other suitableapparatus, that illustrated in Fig. 1 being merely one apparatus which,by virtue of the separate control of the two currents of hot combustiongases by the burners I6 and I1, is particularly adapted to thepracticing of our invention.

The vapor and liquid components, after passing through the heatingstages just described, are recombined and, since the pressure of theliquid component has been reduced by the valve 34, it may be advisableto include a pressurereducing valve 35 in the path of the vapor com-,ponent before recombining the two fractions. Also, a pressure-reducingvalve 36 may be desirable for reducing the pressure of the recombinedcomponents before subjecting them to the remaining stages in thecracking, refining, or converting process.

The subsequent stages of the process for completing the conversion ofthe oil stock forms no part of our invention but, by way of exampleonly, the operation of the particular system described above will bebriefly explained. The recombined vapor and liquid components passingfrom the heating furnace are conducted to the inlet 38 of afractionating tower where they are combined with a component of coolingoil, which may be fresh oil stock or any uncracked or unconvertedfraction from an intermediate stage in the converting process. In thetower 39 they are subjected to live steam from the spray 4|, togetherwith a reflux spray from the nozzle 43, which sprays are effective toaid in the separation of the vapor and liquid components. Theunconvertible or tarry residue passes off through the outlet 44 in thebottom of the tower, preheating the fresh oil stock in the heatexchanger i3, and passing on to any suitable storage chamber.-

The converted components in a vapor state pass through the upper outlet46 of the tower 39 and into the inlet 48 of a fractionating column wherethey are subjected to a reflux spray from the nozzle 5|, which iseffective to condense incompletely converted components or fractions.These unconverted fractions pass out through an outlet in the bottom ofthe column 49 and through a suitable cooling coil 52 to be added to thefresh oil stock. A portion of this unconverted oil may form there-cycling or reflux fluid for the preceding evaporating tower. Theconverted or cracked fractions in a vapor state pass through the upperoutlet 54 of the fractionating column 49 and through a condenser 55where they are liquefied, the liquid condensate or dis- 'tillate passinginto the receiver 51. In this receiver the condensed liquids areseparated by gravity, or otherwise, from entrained vapors which aresupplied to a suitable gas conduit 58. The gasoline is drawn off fromthe outlet 59 while water, condensed from the treating steam, is drawnoff through the outlet 60. A portion of the converted gasoline may beused for the reflux spray 5| of the preceding fractionating column,

as illustrated.

In Fig. 3 is shown a modification of the heating system of Fig. 1,employing two seriesconnected separators. The oil from the heatingsystem is shown, also, as applied to a slightly different cracking orrefining process. As in the arrangement of Fig. 1, the oil stocksupplied to the inlet I is raised to an elevated pressure by the hot oilpump l4, which forces it through bank of tubes 2| for a stage ofpreliminary heating. In this instance, the bank of tubes 2| is connectedto a bank of roof tubes 63 which, in some instances, may be desirable toraise the oil to a satisfactory temperature before it is conducted tothe inlet 64 of the separator S|. The vapor component from the separatorSI passes from the outlet 65 through the banks of tubes 66 and 61,arranged similarly to the banks of tubes 28 and 30, respectively, of theapparatus of Fig. 1. The liquid component passes from the lower outletof the separator Sl, through a bank of roof tubes 68 in the chamber B,thence to the inlet of a second separator S2. The vapor component outlet10 of the separator S2 is connected to a bank of floor tubes H, whilethe liquid component outlet 12 is connected to a second bank of floortubes 13. The outlets l4, l and 16 of the vapor components from theseparators SI and S2 and the liquid component of the separator S2,respectively, are connected to a common conduit or outlet 11. As in thesystem of Fig. 1, pressurereducing valves 18 and 19 are connected in theliquid component outlets of the separators SI and S2, respectively,while the pressure-reducing valves 80 and 8| are connected in theoutlets 14 and 15 of the vapor components from the separators SI and S2,respectively, before recombining the several components in the commonoutlet 11. The operation of the heating apparatus just described issubstantially similar to that of Fig 1 with the exception that, in thisinstance, an additional separating and heating stage is added, thusseparating the oil stock into three fractions or components, each ofwhich is substantially more homogeneous as regards its physical andthermal characteristics than the fresh oil stock. For example, the vaporcomponent from the separator SI, heated in the banks of tubes 69 and 61,may comprise a mixture of only the lightest fractions, which may becracked or refined at a relatively high temperature. The liquidcomponent from the separator Si, passing through the bank of tubes 68,is raised to a somewhat higher temperature, vaporizing slightly heavieror intermediate fractions which are separated in the separator S2 fromthe heaviest fractions, these intermediate fractions, in a vaporizedstate, being finally heated in the bank of tubes H at an intermediatetemperature. The heaviest fractions, passing from the liquid outlet 12of the separator S2, may be heated more moderately to avoid overcrackingor coking thereof. The several components are then recombined in the common outlet T! from which they pass to the remainder of the cracking orrefining process.

It will be understood that the arrangements and connections of theparticular banks or groups of tubes utilized'in the several heatingstages just described above are subject to wide variations to suit therequirements of the particular heating furnace and the particular oilstock being treated. It will be clear, also, that while the banks oftubes 63, 96 and 88 are arranged similarly to the banks of tubes 28 and3| of Fig. 1, and receive heat preponderantly by radiation, while thetubes 61 and 13 are disposed similarly to the banks of tubes 30 and 33of Fig. 1 and receive heat substantially solely by radiation, thedisposition ofthese several banks or groups of tubes may be varied tovary the mode of heat transfer, as by radiation, convection or combinedradiation and convection, in accordance with the requirements of theparticular system.

It will be clear, also, that, while we have illustrated the use of twoseparators for breaking down the fresh oil stock into three componentsor fractions for separate heating to cracking or convertingtemperatures, the system may be extended to employ any desired number ofseparators to separate the oil stock into a corresponding number offractions, each having a homogeneity within any desired limits.

' By way of further example, there is disclosed a modified system forcompleting the conversion of the oil. In this system, the oil, heated asjust described, is passed from the common outlet 11 to a reaction ordigesting chamber 82 where the vapor and liquid mixture reaches a stateof equilibrium and the cracking process proceeds without the addition offurther heat. The combined liquid and vapors pass from outlet of thereaction chamber 82 into the inlet 83 of a flash chamber 84, a supply ofcooling oil from the conduit 85 also being connected to the inlet 83.The cooling oil may be supplied from the fresh oil stock or from anyother intermediate stage of the conversion process.

In theflash chamber, the vapor and liquid mixture under high pressureexpands rapidly, vaporizing all of the components except the heavy,

tarry residues, which are drawn off from the lower outlet of the chamber84. The converted and vaporized fractions pass upwardly through theoutlet 86 and combine with fresh cooling oil from the inlet 81 connectedwith the inlet 88 of a fractionating column 89. A reflux inlet 90 isconnected to a spray 9| disposed in the top of the column 89, while aliquid outlet 92 receives the unconverted or heavier fractions, whichare recombined with the fresh oil stock. The lighter converted orcracked fractions 'pass upwardly through the outlet 93 to a condenser94, and the condensed liquids therefrom flow through an inlet 95 of acondensate or distillate receiver 96, where theyare separated into gas,gasoline and water, as in the system of Fig. 1.

While we have described what we at present consider the preferredembodiments of our invention, it will be obvious to those skilled in theart that various changes and modifications may be made without departingfrom our invention and we, therefore, aim in the appended claims tocover all such changes and modifications as fall within the true spiritand scope of our invention,

What we claim is:

1. An oil-heating system comprising a heating chamber, means for passingtherethrough a plurality of independently controllable currents of hotcombustion gases, said chamber comprising a zone traversed by thecombined currents of gases, oil-conducting heat-absorption structuredisposed in said zone to be heated substantially by convection, meansconnected with said absorption structure for separating the oiltherefrom into liquid and vapor components, oil-conductingheat-absorption structure connecting the liquid component outlet of saidseparating means and disposed below and without one of said currents ofgases and absorbing heat substantially solely by radiation from said oneof said currents of gases, other oil-conducting heat-absorptionstructure connected to the vapor component outlet of said separatingmeans and disposed below and Without the other of said current of gasesand absorbing heat substantially solely by radiation from said other ofsaid currents of gases, said last-named heat-absorption structures beingdirectly connected to a common outlet for immediate mixture of saidvapor and liquid components after their passage through said structures,pressure-producing means individual to the system connected to saidfirst-named structure for producing flow under pressure of charge-oiland its said components through said oil-conducting structures.

2. In an oil-heating system,'the method of cracking oil which comprisesburning fuel at separate points to generate heat, passing the currentsof hot combustion gases through a plurality of zones, certain of whichare individual to said currents and one of which is common I to all ofsaid currents of gases, elevating chargeoil to an initial pressuresuflicient to produce flow thereof through the system, passing oilthrough heat absorption structure located in said common zone,transferring by convection a portion of the generated heat to saidstructure in said common zone to convert the oil into liquid andvaporous components, separating the heated oil into liquid and vaporcomponents, utilizing said pressure separately to pass all of saidcomponents through heat absorption structures located in other of saidzones, individually transferring heat substantially solely by radiationfrom said gases to said structures located in said other zones toelevate the components to their respective conversion temperatures, andwhile at their said conversion temperatures recombining all of saidcomponents for further treatment.

3. In an oil-heating system, the method of cracking oil which comprisesburning fuel at separate points and different rates to produce inoil-conversion zones independently controlled temperatures, passing thecurrents of hot combustion gases through a plurality of said zonescertain of which are individual to said currents and, one of which iscommon to all of said currents of gases, the temperature of one of saidcurrents of gases being higher than the temperature of the other,passing oil under substantial initial pressure through heat absorptionstructure located in said common zone, transferring by convection aportion of the generated heat to the structure in said common zone toconvert the oil into liquid and vapor components, under pressuremechanically separating the heated oil into said liquid and vaporcomponents, utilizing said pressure to pass said vapor component throughheat absorption structure exposed to and substantially out of the pathof the higher temperature combustion gases, utilizing only a part ofsaid pressure to pass said liquid component through heat absorptionstructure exposed to and substantially out of the path of the lowertemperature combustion gases, individually transferring heatsubstantially solely by radiation from said gases of differingtemperature to said liquid and vapor containing structures individuallyto elevate them to their conversion temperatures, and under pressurerecombining said components while at their said conversion temperaturesfor further treatment.

4. An oil heating system comprising a single heating compartment, bafflestructure forming within said compartment separate fire chambers, and aconvection chamber, adjustable fuel-burners for producing currents ofhot gases individual to said fire chambers, the combined currents of hotgases passing through said convection chamber, oil-conductingheat-absorption structure disposed within one of said chambers andabsorbing a part of the generated heat to convert the oil into vaporousand liquid components of substantially different boiling ranges, meansfor subjecting charge-oil to substantial initial pressure, a mechanicalseparator connected to said heat absorption structure for separatingsaid components from each other, oil-conducting heat absorptionstructures disposed within said fire chambers and without the currentsof gases individual thereto, and individual means connected to saidseparator for conducting selected vaporous and liquid components of theoil to said last-named heat absorption structures, the components of theoil by said initial pressure flowing through said structures, each ofsaid last-named structures absorbing substantially solely by radiationgenerated heat in amounts sufiicient further to convert the respectivecomponents into additional components of still other boiling rangeswithout overcracking thereof, the amounts of heat generated in each firechamber being dependent upon the setting of the adjustable burnersindividual thereto, to provide a wide range of temperature control ofsaid oil-conducting heat absorption structures disposed in said fire andconvection chambers and a common outlet, directly connected to saidstructures, within which said selected vaporous and liquid componentscommingle while at their conversion temperatures.

5. A system of heating oil and components thereof to conversiontemperatures comprising a single heating compartment, bafile structureforming within said compartment separate fire chambers and a convectionchamber between said fire chambers, adjustable fuel-burners forproducing currents of hot gases individual to said fire chambers, thecombined currents of gases passing through said convection chamber,oilconducting heat-absorption structure within said convection chamber,means producing a substantial initial pressure upon charge-oil to forceits passage through said structure, said structure absorbing heat fromsaid gases-to convert the oil into vaporous and liquid components ofsubstantially different boiling ranges, a separator for dividing saidvaporous and liquid components, means connecting said structure to saidseparator for passage of the oil thereto, oil-conducting heat-absorptionstructure in each of said fire chambers disposed along the floor thereofand without the current of hot gases individual thereto, meansconnecting an absorption structure in one fire chamber to said separatorfor passage of a liquid component therethrough, and for connecting anabsorption structure in the other fire chamber for the passage of avaporous component therethrough, said initial pressure producing meansalone producing passage of said oil and its components through saidstructures and said separator, the burners individual to each firechamber being adjusted to control the temperature rise of saidcomponents further to convert the respective vaporous and liquidcomponents without over-cracking thereof, and means, forming a commonoutlet to said structures, within which said liquid and vaporouscomponents commingle While at their respective conversion temperatures.

6. On oil heating system comprising a single heating compartment, bafliestructure forming within said compartment separate fire chambers and aconvection chamber between said fire chambers, adjustable fuel-burnersfor producing currents of hot gases individual to said fire chambers,the combined currents of gases passing through said convection chambermeans for producing a substantial initial pressure upon the charge-oil,oil-conducting heat-absorption structure connected to said pressureproducing means and disposed within said convection chamber forabsorbing heat from said gases to convert the oil into vaporous andliquid components of substantially different boiling ranges, separatingmeans connected to said structure for dividing said converted oil intoat least one liquid component and at least two vaporous components, heatabsorption structures in each of said fire chambers, individual meansconnecting said lastnamed structures for passage of the vaporouscomponent having the lowest boiling range to heat absorption structuredisposed along the floor of, and without the path of gases in, one firechamber, and for passage of other of the vaporous components and saidliquid component to said other structures disposed without the currentof hot gases within said other fire chamber, said pressure producingmeans alone being effective to produce under pressure, flow of saidcharge-oil and its said components through the system, and saidfuel-burners being adjusted for production of a substantially highertemperature in one fire chamber than in the other for further conversionof said components without overcracking thereof, and means forming acommon outlet to at least said structures through which pass said,vaporous components for mixture of at least said vaporous componentswhile at their conversion temperatures? '7. In an oil heating system,the method of heating chargeeil to cracking temperature which ccmprisesinitially raising the charge-oil to a pressure sufficient to produceflow of the oil from 'inlet to outlet of the systemfi'n one some of thesystem transferring heat toffthe oil to produce conversion thereof intoliquid and vapor components, in a neutral temperature and reaction zonemechanically separating the heated oil in a plurality of successivestages into liquid and vapor components of respectively differingconversion temperature, in different zones of the system transferringheat to said respective vapor components individually to elevate them totheir respective conversion temperatures, reducing the pressure of theliquid component of each stage and thereafter transferring heat toeachsaid liquid component before enteringthe next succes sive stage, andin a neutral temperature and reaction zone recombining the vaporcomponents of the several stages with the liquid component of the finalstage for further treatment.

8. Ai system of heating oil and components thereof to conversiontemperatures comprising currents of gases passing through saidconvection chamber, tubular oil-conducting heat-absorption structurewithin said convection chamber, tubular oil-conducting heat-absorptionstructures lo cated adjacent the roof and floor of eafch of said firechambers, means for passing elharge-oil through said first-namedstructure to convert the oil into components of substantially diiferentboiling ranges, means for simultaneously passing one of said componentsin series through the structures adjacent the roof and floor of one ofsaid fire chambers, and the other of said components in series throughthe tubular structures adjacent the roof and floor of the other firechamber, thereby to procure by adjustment'of said fuel burnersindependent pontrol of the temperature rise of said components duringtheir passage through said' separate fire chambers, and means forming acommon outlet to said structures within said fire chambers for immediatemixture therein of said components after passage through said last-namedstructures. Y 'ARTHUR E. NASH. i

' FRANKLIN EFSHELLY.

. v CERTIFICATE OF CORRECTION. Patent No 2,1 2,961 october 14, 19 8.

' ARTHUR NASH, Er n.

It is hereby dert ified th gt 'eri'or appear; in the rintedspecification of the abve numbered patent requiring oi-retipn asfollows: Page 2,'firt columh, line 25 strik out the word. "mechaziiali"insert the 'sanie after the article j'a", line 21;; page 5,-secondco1mnn, 11ne h2, c laim 6 for "Oh" r'ead An; line 14.9, same claim,after chaYnbeh" inseht acomma; and that the said. Lettehs PatentShouidbe read with thi', corr ectio n thre'in that the same" may'conformto the re cor'cl f the ca'e in 15115 Patent Office.

Signed and. sealed th i ,s" 6th day of Decen xb er, A. D.- ;L958. v 1

Henry Van Arsdale (Seal); I Acting Cpmmissionef of'Patentm

